Refrigerating apparatus



Sept. 29, 1936. q:u 2,055,499

REFRIGERATING APPARATUS Filqd March 17,.1933 3 Sheets-Sheet 1 Sept.29,1936. J. G. KING 2,055,499

REFR IGERAT I NG APPARATUS Filed March 17, 1953 5 Sheets-Sheet 2 Sept.29, 1936. J, 13, K 2,055,499

REFRIGERATING APPARATUS Filed March 17, 1953 s Sheets-Sheet 5 &

INVENTOR HIS ATTORNEYS.

meme Sept. 29. 1936 V PATENT FFICE REFRIGERATING APPARATUS Jesse G.King, Dayton, Ohio, assignor, by mesne assignments, to General MotorsCorporation, a corporation of Delaware Application March 17, 1933,Serial No. 661,209 17 Claims. (01. 62-126) This invention relates torefrigerating systems and more particularly to heat exchange units suchas evaporators for such systems.

In the construction of evaporators for refrigerating systems of the typeincluding a plurality of pipes or conduits for distributing refrigerantto be vaporized in the evaporator it has been common practice to out orstamp blank pieces of metal from sheets thereof and to punch or formholes in the blanks so that they can be assembled onto the refrigerantpipes or conduits. The blanks thus produced provide fins for increasingthe cooling surface area of such evaporator structures as is wellrecognized in the art. While such structures have been considered to besatisfactory it has nevertheless been found that the portion of theindividual blank fins immediately surrounding the refrigerant conduitsare substantially the only part of the individual fins which areeffective or 20 efiicient for rapidly absorbing and transmitting heat tothe refrigerant in the conduit or conduits of the evaporator. In otherwords a substantial temperature difference or gradient between portionsof the blank fins adjacent the refrigerant 05 conduits and portionsthereof more remote from the refrigerant conduits is inherent in suchfin structures. A predetermined number of such blank fins are ordinarilyassembled on the refrigerant conduits constituting an evaporator toprovide an evaporator of a predetermined cooling capacity. Since theportions of such blank fins remote from a conduit or conduits of theevaporator, which portion is inefiective, constitutes a large portion ofsuch fins it is important to devise some means to render these portionsof fins efficient or to enable these portions of the fins to be used ina more advantageous manner in the construction of evaporators.

The object of my invention therefore is to provide a heat exchange unitsuch as an evaporator of a refrigerating system wherein the effectivecooling area thereof is materially increased without materiallyincreasing the amount of metal employed in the construction thereof.

A further object is to provide a method of construction and particularlya method of fin construction whereby the heretofore ineffective portionsof the metal fins are utilized for the formation of additional fins.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings, wherein a preferred form of the present invention is clearlyshown.

In the drawings:

Fig. 1 discloses an evaporator constructed in accordance with myinvention adapted to be connected to a refrigerating system showndiagrammatically;

Fig. 2 is a top plan view of the evaporator shown in Fig. 1;

Fig. 3 is a front view of the evaporator;

Fig. 4 discloses a conventional form of blank fin heretofore employed inthe construction of evaporators;

Fig. 5 discloses a blank fin cut or formed in accordance with thepresent invention to provide two individual fins;

Fig. 6 is a sectional view through my improved evaporator and is takenon the line 6-6 of Fig. 2;

Fig. '7 is a sectional view through my improved evaporator and is takenon the line 1-1 of Fig. 2;

Fig. 8 is an end view of a modified form of evaporator constructed inaccordance with my invention;

Fig. 9 is a side view of the evaporator shown in Fig. 8;

Fig. 10 is an end view of a unit employed in the construction of theevaporator shown in Figs. 8 and 9;

Fig. 11 is a side view of the unit shown in Fig. 10;

Fig. 12 is an end view of another unit employed in the construction ofthe evaporator shown in Figs. 8 and 9; and

Fig. 13 is a side view of the unit shown in Fig. 12.

Referring to the drawings for the purpose of illustrating my invention Ishow in Fig. 1 a refrigerating system including the customary comonlypart of the individual fins which are effective An electric motor i8operates the compressor [5 through belt and pulley connections l9 and2i. Liquid refrigerant is conducted to the evaporator l1 through thepipe line 22 and gaseous or evaporated refrigerant is withdrawn from theevaporator ll, by compressor 15, through the vapor pipe line 23. Anexpansion valve 24 is interposed in the pipe line 22 and is actuated inresponse to pressures within the evaporator H for admitting liquidrefrigerant to the evaporator. The operation of valve 24 is adapted tobe modified in accordance with the temperature of the evaporatoradjacent the outlet thereof. A thermostat 25 (see Fig. 2) is connectedby the pipe 26 to the valve 24 for this purpose. The operation of motorl8 and consequently compressor I5 is controlled by a switch 28 which isactuated by movement of a bellows 21, communicating with the interior ofthe evaporator II or with the vapor line 23, in response to pressureswithin the system. As long as the system is functioning normallyexpansion valve 24 opens and closes automatically in response topressures in the evaporator and controls the flow of liquid refrigerantthereto. During normal operation of the system the compressor starts andstops in response to pressures in the low pressure portion of the systemto maintain the evaporator between predetermined temperature limits.

The evaporator I! in the present disclosure includes two headers 3| and32 which are in the form of cylinders disposed one above the other. Thelower header 3| is provided with an inlet connection 33 for receivingliquid refrigerant from the expansion valve 24 and for directing same tothe evaporator. The upper header 32 is provided with a gaseousrefrigerant outlet connection 34 adapted to communicate with the vaporpipe line 23 of thesystem. The outlet connection 34 includes anextension or stand-pipe 35 which extends to a point near the top ofheader 32 (see Fig. 1) so as to prevent entrance of liquid refrigerantinto the vapor-return conduit 23. A plurality of straight lengths ofpipe 36 are connected to the lower header 3| and extend outwardly orlaterally therefrom. A plurality of similar pipes 31 are connected tothe upper header 32 and extend outwardly therefrom. The pipes orconduits 36 and 31 extend parallel to one another and are arranged invertical aligned pairs along the length of the headers and the upper andlower pipes of each of the pairs are connected at their outer ends byU-shaped connections 38. The legs of the U-shaped connections 38 areinserted into and secured to the ends of pipes 36 and 31 in any suitablemanner to provide a plurality of refrigerant conveying conduits or ductsconnected in parallel with the headers 3| and 32 (see Figs. 2 and 3).

The upper header 32 of the evaporator is provided with a baflie 4| (seeFig. 1) which extends horizontally across the interior thereof and issecured to the walls of the header. Baflie 4| is provided with anopening for receiving the extension or stand-pipe 35 which cooperateswith the outlet connection 34. This baiile 4| ispositioned above thepoint of communication of pipes 31 with header 32 and extends from thefront end wall of header 32 to a point spaced from the rear end wallthereof. The space between the end of baiile 4| and the rear wall ofheader 32 provides a passage 42 for permitting refrigerant to flow frombelow the battle to the opening in stand-pipe 35 communicating with theoutlet connection 34 in header 32 (see Fig. 1). A tubular member 43 issealed to the front end wall of header 32 (see Fig. 2) and extends intothe header above baffle 4|. Member 43 is closed at itsinner end to forma wall for the reception of the thermostat 25 which is adapted to modifythe action of expansion valve 24 in response to temperatures of theevaporator ll. Liquid refrigerant is adapted to be maintained by theexpansion valve 24 and the thermostat 25 at a substantially constantlevel below and adjacent to the baille 4| so as to maintain theevaporator in a flooded condition at all times. Thermostat 25 isresponsive to the flow of liquid refrigerant above the ballle 4| toactuate expansion valve 24 into closed position to stop the flow ofliquid refrigerant to the evaporator and to prevent liquid refrigerantfrom entering the suction or vapor pipe 23. The

control of a refrigerating system and the maintenance of liquidrefrigerant in an evaporator of the type disclosed may be more fullyunderstood by reference to the patent to Harry B. Hull, No. 1,834,949 ofDecember 8, 1931. I have disclosed one form of evaporator constructionfor illustrating my invention but I wish it to be understood that othervarious forms may also come within the realm of my invention.

My invention is particularly directed to the method of producing finsand the arrangement thereof on the refrigerant conveying or distributingconduits or ducts of an evaporator with the object in view of reducingto a minimum the material employed in the construction thereof while atthe same time obtaining maximum ciliciency of the evaporator. With theforegoing in mind and referring to Fig. 4 of the drawings, I have showna blank piece of thin metal 46 of the type heretofore employed toprovide a fin or fins for 'evaporators. As before stated this blank 46is ordinarily cut from sheets of metal and holes 41 punched therein topermit insertion of the refrigerant conveying conduits or ducts thereinso that the fin or fins will bridge the plurality of ducts constitutingthe evaporator structure. I have found that substantially the onlyportions of such blanks 46, when assembled onto the conduits ofevaporator structures, which are effective or eflcient for absorbing andconducting the heat, from the medium to be cooled by the evaporator, torefrigerant contained in the evaporator are those portions immediatelyadjacent or surrounding the refrigerant ducts. I have indicated theseeffective portions of the blanks or fins 46 as being the portionssubstantially within the area defined by the dot and dash lines 46 inFig. 4. In view of the fact that substantially one half of the area orheat absorbing surface of the blank or fin 46 is not effective for thepurpose described it is obvious that two fins may be produced from thisblank or from a blank of substantially the same size providing asatisfactory method of cutting the blank could be worked out.

Therefore in order to produce or obtain two fins from the blank 46 shownin Fig. 4 or from a blank of substantially the same form and size I cutor stamp the two fins 5| and 52 shown in Fig. 5 from a sheet of thinmetal of slightly larger dimension than the dimension of the sheet fromwhich the blank 46 is cut. The dimension of the sheet required to obtainthe two fins 5| and 52 over the dimension of the blank 46 is relativelysmall and is indicated by the dot and dash lines 53 shown in Fig. 5.Each fin 5| and 52 includes a continuous edge portion 54 and outwardlyprojecting diamond-shaped leg portions 55. Obviously the shape or formof the legs 55 may be varied if desired to meet varying conditionswithout departing from my invention. Holes 56 in fin 5| and holes 57 infin 52 are punched in the fins preferably simultaneously with thecutting of the sheet into the individual fins. While I prefer to punchholes 56 and 51 simultaneously as explained, it is to be understood thatthese holes may be punched prior to severing the blank 46 or they may bepunched in the fins 5| and 52 after these fins have been cut from theblank. The holes 56 in fin 5| are equally spaced apart both horizontallyand vertically. Holes 51 in fin 52 are spaced apart in accordance withthe spacing of holes 56 in fin 5|. The particular design of the die ortool employed for cutting the two individual fins 5| and 52 or theparticular cuts through the sheet of metal,

together with the equal or similar spacing of the A predetermined numberof the fins 5| and 52 are cut from a sheet of thin metal of good heatconductivity, preferably copper, and are assembled onto the refrigerantconveying or distributing ducts 36 and 31. The assembly of fins 5| and52 onto ducts or pipes 36 and 3! of the evaporator is of course carriedout prior to securing the U-shaped connections 38 to the pipes, or

prior to securing the pipes 36 and 31 to the headers 3| and 32, andthese fins may be assembled onto the pipes in any desired manner. Thediamond-shaped legs 55 of fins 5| and 52 may all be directed in the samegeneral direction if desired, but are preferably assembled onto thepipes 36 and 3! as disclosed in Figs. 6 and 7 so that the legs 55 of onefin are directed downwardly while the legs 55 of the adjacent fin aredirected upwardly. This arrangement is preferable in order to produce asymmetrical evaporator of neat appearance.

After the assembling operation of the fins onto the pipes 36 and 31 ofthe evaporator has been completed, it being understood of course thatthe fins are forced onto the ducts or pipes or that the pipes are forcedinto the holes in the fins to insure good thermal contact therebetween,angle members 6| are placed at the corners of the fins to protect thefins against damage during manipulation of the evaporator in the factoryand during shipment thereof. The angle members 6| extend across all thefins included in the construction of the evaporator and may be held inplace at the corners of the fins by any suitable means. In the presentdisclosure I have shown rods 62 comprising a threaded end whichprotrudes through an opening in the angle members 6| and receives a nut63. The opposite ends of rods 62 are formed into a hook portion 64 forencircling and gripping the pipes 36 and 31 of the evaporator. The nuts63 upon-being drawn up tight against member 6| firmly clamps member 6|against the corner of the fins 5| and 52.

An evaporator constructed in accordance with the foregoing descriptionis intended for installation in a refrigerator cabinet wherein a naturalcirculation of air is created by the cooling eifect produced by theevaporator. However, my invention is not limited to the particularevaporator hereinbefore described because various modifications may bemade incorporating the principles of my invention. For example, I haveshown in Figs. 8 and 9 of the drawings one form of modified evaporatorstructure. The evaporator disclosed in Figs. 8 and 9 is designed forinstallation in a refrigerator cabinet or the like wherein a forcedcirculation of air is created by means such as fans. In this type ofinstallation the number of refrigerant conduits and the number of finsin contact with-the refrigerant conduits of the evaporator may begreatly increased for providing ample cooling surface to insure coolingof the increased volume of air circulated or forced over the evaporator.Therefore the unitary evaporator structure shown in Figs. 8 and 9 isconstructed of two sub-assemblies or units II and 12. The sub-assemblyor unit II is shown in Figs. 10 and 11 while the other unit 'I2,is shownin Figs. 12 and 13. The unit H includes a plurality of straight lengthsof ducts or pipe 13 upon which are mounted a plurality of fins 14. The

unit I2 includes a plurality of straight lengths of ducts or pipe I5upon which are mounted a plurality of fins 16. Each of the fins 14 is acomplemental part of one of the fins 16 and these fins may be producedfrom a single sheet of metal as hereinbefore described. It will he notedthat the unit ll comprises less refrigerant pipes than the unit 12. Thisis for the purpose of permitting unit II to be telescoped or moved intounit 12 substantially within the boundary thereof to produce the unitaryevaporator structure disclosed in Figs. 8 and 9. It is obvious from thedetailed showing of the individual units H and I2 and from theparticular fin design that the conduits 13 of unit Il may be moved intothe openings or slots between the legs of fins 16 on unit 12. Aftermoving unit 1| into engagement with unit '52 the refrigerant conveyingpipes 13 and 15 are connected together at each end of the evaporator byelbows or U-shaped members TI and 18 to provide a compact unitarystructure consisting of a continuous conduit or a series of path of fiowfor refrigerant through the evaporator. One end of the continuousconduit is provided with a coupling 19 and the other end of the conduitis provided with a coupling 8|. The coupling I9 is adapted to beconnected with an exfrigerating system disclosed and the coupling 6| isadapted to be connected with the refrigerant vapor-return conduit 23 ofthe system. Since this latter described evaporator is primarily intendedfor installation in conjunction with forced circulation of air thereoveror therethrough its compactness provides a maximum of heat ab sorbingsurfaces or areas within a minimum amount of space which is a desirablefeature of such structures.

It will be apparent from the foregoing that I have provided an improvedevaporator, the fin surface of which is constructed of less orsubstantially one-half the material heretofore used in the constructionof such e aporators while at the same time maintaining the sameefficiency obtained from evaporators of known structure. My improvedevaporator structure also creates an improved and increased aircirculation within refrigerator cabinets due to the fact thatsubstantially all of the heat absorbing surfaces of the fins are of thesame temperature and are therefore fins more efficient for absorbing andtransmitting heat to the refrigerant within the refrigerant expansionconduits of the evaporator thus causing the air to move more rapidlythereover and therethrough. Since all of the heat absorbing surfaces ofthe fins of my improved evaporator are at substantially the sametemperature as the temperature of the refrigerant within the evaporatorthe temperature of the evaporator can be maintained at a higher degreethan prior evaporators wherein a temperature gradient between certainportions of the fins is inherent. By cutting or forming the fins inaccordance with my invention so that certain fins of the evaporator area complemental part of certain other of the fins I provide for themounting of twice as many fins on the evaporator without materiallyincreasing the weight thereof and at substantially the same cost asproviding the required number of fins for evaporatorsheretofore known.

While the forms of embodiments of the invention as herein disclosed.constitutes preferred forms, it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

1. The method of producing a plurality of fins from a single plate whichcomprises, forming a plurality of rows of openings in the plate forreceiving a plurality of ducts, forming a second plate from portionswithin the boundary of the first plate remote from the portions thereofadjacent the openings therein and between each of the plurality of rowsof openings to provide two fins one of which is a complemental part ofthe other, and forming openings in the second plate for receiving theplurality of ducts adapted to be received in the openings of the firstplate.

2. The method of making a unitary heat exchange structure whichcomprises, arranging a plurality of refrigerant conveying ducts inparallel elation and assembling a plurality of fins ther on transverselyto the longitudinal attis the eof to provide a first unit, arranging aplural y of refrigerant conveying ducts in parallel relation andassembling a plurality of fins thereon transversely to the longitudinalaxis thereof to provide a second unit, moving one of the unitssubstantially within the boundary of the other of the units andconnecting the ducts of one unit to the ducts of the other unit toprovide a unitary structure.

3. Tube heat exchanger, particularly for refrigerating systems,comprising a plurality of fins having openings therein receiving aplurality of 'ubstantially parallelly extending spaced apart r0 s oftubes for increasing the heat transfer surface of the exchanger,characterized by the fact that one fin is formed as a complemental partof another fin from a predetermined sheet area and the complemental finhas a row of tube receiving openings provided in material cut from saidsheet area between the two rows of tube receiving openings in the onefin and in which row each tube receiving opening in said sheet area isstaggered with respect to the tube receiving openings in each row of theone fin.

4. Tube heat exchanger according to claim 3, characterized by the factthat the boundary of the material of the fins surrounding each of thetube receiving openings is rhomboidal in form and has the tube receivingopenings at the center of the rhombus.

5. An evaporator for refrigerating systems including a plurality ofparallelly arranged refrigerant conveying ducts, one or more pairs offins having a plurality of rows of openings fitting over and engagingthe plurality of refrigerant ducts, each pair of fins being formed froma sheet area of the extent ordinarily employed to form one fin, and oneof the fins of each pair thereof comprising a portion removed from saidsheet area between the rows of openings provided therein for the otherfin which is normally inactive when said one fin is used as a singlefin.

6. An evaporator for refrigerating systems according to claim 5, inwhich each fin of said pairs thereof consists of a web with extendingportions formed of the material of said sheet area between the rows ofopenings in one fin being of rhomboidal form and having the refrigerantduct receiving openings in each extending portion at the center of therhombus.

7. An evaporator for refrigerating systems according to claim 5, whichconsists of two subunits so telescoped that their fins are displacedrelatively to one another, and the refrigerant ducts of one unit extendthrough spaces in the fins of the other unit.

8. An evaporator for refrigerating apparatus including a plurality ofparallelly arranged refrigerant conveying ducts, a fin secured inintimate thermal contact to certain of said ducts, a second finindependent of said first named fin secured in intimate thermal contactto certain of said ducts, both of said fins having a plurality oftransverse and a plurality of perpendicular rows of openings therein forthe reception of said refrigerant ducts, said second named fin beingcomplementary to said first named fin and including portions removedfrom said first named fin remote from and between each of the pluralityof rows of openings therein adapted to be secured to said ducts.

9. An evaporator for refrigerating apparatus including a plurality ofparallelly arranged refrigerant conveying ducts, a fin secured inintimate thermal contact to said plurality of ducts, a second finindependent of said first named fin also secured in intimate thermalcontact to said plurality of ducts, both of said fins having a pluralityof transverse and a plurality of perpendicular rows of openings thereinfor the reception of said refrigerant ducts, said second named fin beingcomplementary to said first named fin and including portions removedfrom said first named fin remote from and between each of the pluralityof rows of openings therein adapted to be secured to said ducts.

10. An evaporator for refrigerating apparatus including a plurality ofparallelly arranged refrigerant conveying ducts, a fin secured inintimate thermal contact to certain of said ducts, a second finindependent of said first named fin secured in intimate thermal contactto certain other of said ducts, both of said fins having a plurality oftransverse and a plurality of perpendicular rows of openings therein forthe reception of said refrigerant ducts, said second named fin beingcomplementary to said first named fin and including portions removedfrom said first named fin remote from and between each of the pluralityof rows of openings therein adapted to be secured to said ducts.

11. An evaporator for refrigerating apparatus including a plurality ofparallelly arranged refrigerant conveying ducts, a group of fins securedin intimate thermal contact to certain of said ducts and extendingtransversely to the longitudinal axis thereof, a second group of finssecured in intimate thermal contact to certain of said ducts andextending transversely to the langitudinal axis thereof, the fins ofeach group thereof having a plurality of transverse and a plurality ofperpendicular rows of openings therein for the reception of saidrefrigerant ducts, a certain individual fin of said second named groupbeing complementary to a certain individual fin of said first namedgroup and including portions removed from said certain fin of said firstnamed group remote from and between each of the plurality of rows ofopenings therein adapted to be secured to said ducts.

12. An evaporator for refrigerating apparatus including a plurality ofparallelly arranged refrigerant conveying ducts, a group of fins securedin intimate thermal contact to certain of said ducts and extendingtransversely to the longitudinal axis thereof, a second group of finssecured in intimate thermal contact to certain other of said ducts andextending transversely to the longitudinal axis thereof, the fins ofeach group thereof having a plurality of transverse and a plurality ofperpendicular rows of openings therein for the reception of saidrefrigerant ducts, a certain individual fin of said second named groupbeing complementary to a certain individual fin of said first namedgroup and including portions removed from said certain fin of said firstnamed group remote from and between each of the plurality of rows ofopenings therein adapted to be secured to said ducts.

13. An evaporator for refrigerating apparatus including a plurality ofparallelly arranged refrigerant conveying ducts, a group of fins securedin intimate thermal contact to said plurality of ducts and extendingtransversely to the longitudinal axis thereof, a second group of finsalso secured in intimate thermal contact to said plurality of ducts andextending transversely to the longitudinal axis thereof, the fins ofeach group thereof having a plurality of transverse and a plurality ofperpendicular rows of openings therein for the reception of saidrefrigerant ducts, a certain individual fin of said second named groupbeing complementary to a certain individual fin of said first namedgroup and including portions removed from said certain fin of said firstnamed group remote from and between each of the plurality of rows ofopenings therein adapted to be secured to said ducts.

14. An evaporator for refrigerating apparatus comprising in combination,a pair of headers, a plurality of refrigerant conveying ducts connectedin parallel to said headers, a fin secured in intimate thermal contactto said ducts and extending transversely to the longitudinal axisthereof, a second fin independent of said first named fin also securedin intimate thermal contact to said ducts and extending transversely tothe longitudinal axis thereof, both of said fins having a plurality oftransverse and a plurality of perpendicular rows of openings therein forthe reception of said refrigerant ducts, said second named fin beingcomplementary to said first named fin and including portions removedfrom said first named fin remote from and between each of the pluralityof rows of openings therein adapted to be secured to said ducts.

15. An evaporator for refrigerating apparatus comprising in combination,a pair of horizontally disposed headers extending parallel to oneanother, a plurality of refrigerant conveying ducts connected inparallel to said headers and extending laterally therefrom, a finsecured in intimate thermal contact to said ducts and extendingtransversely to the longitudinal axis thereof, a second fin independentof said first named fin also secured in intimate thermal contact to saidducts and extending transversely to the longitudinal axis thereof, bothof said fins having a plurality of transverse and a plurality ofperpendicular rows of openings therein for the reception of saidrefrigerant ducts, said second named fin being complementary to saidfirst named fin and including portions removed from said first named finre mote from and between each of the plurality of rows of openingstherein adapted to be secured to said ducts.

16. A method of making fins each adapted to cooperate with a pluralityof the tubes of a tubular heat exchanger, characterized by the fact thatfrom a rectangular sheet area extensions or fiaps are cut out on acommon web portion coinciding with one long side of the sheet area, thatpart of the sheet area coinciding with the other long side forming a webportion for sheet parts located between said extensions for the purposeof obtaining without loss of material and from a sheet area ofsubstantially the same size as previouslyused for the formation of onefin two substantially uniform fins one of which is formed from portionsinactive for the heat transferring action of the other fin.

17. A method of making fins each adapted to cooperate with a pluralityof the tubes of a tubular heat exchanger, characterized by the fact thatfrom a rectangular sheet area rhomboidal extensions or flaps are cut outon a common web portion coinciding with one long side of the sheet area,that part of the sheet area coinciding with the other long side forminga web portion for sheet parts located between said extensions for thepurpose of obtaining without loss of material and from a sheet area ofsubstantially the same size as previously used for the formation of onefin two substantially uniform fins one of which is formed from portionsinactive for the heat transferring action of the other fin.

JESSE G. KING.

CERTIFICATE OF CORRECTION.

Patent No. 2,055,499. September 29, 1936.

JESSE G. KING.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 1second column, line 38, strike out the words '.'only part of theindividual fins which are effective" and insert instead the syllable,words and period pressor 15, a condenser 16 and an evaporator 17. andthat the said Letters Patent should be read with this correction thereinthat the same may conform to the record of the case in the PatentOffice.

Signed and sealed this 1st day of December A. D. 1956.

Henry Van .arsdale (Seal) Acting Commi ssioner of Patents.

